It is cultural. White folk feel more empowered and free to talk about it. Black folk are busy trying to be normal to get by in life.

Look what goes on in South America. Lots of sightings and abductions. Race has nothing to do with it there.

I am sure it has to do with literacy rates also. If you are not comfortable with the written word, and if you are not comfortable with society in general, you are less likely to report what you have seen and experienced.